1. Field of the Invention
The present invention relates generally to plumbing tools and more particularly, to a plumbing tool for removing a compression fitting from a pipe.
2. Description of the Related Art
A plumbing system for a building or house typically includes a network of interconnected pipes distributed throughout the structure. It is generally desirable to control the flow of fluid through the pipes with valves. Accordingly, one or more valves may be connected to the pipes to control the flow of fluid therethrough. In order to form a fluid-tight seal between the valve and the pipe, a compression fitting or ferrule is typically disposed within the pipe-valve connection.
As used herein, a ferrule refers to a band, typically formed of a metallic material, that is circumferentially disposed about the pipe at the connection between the pipe and the valve. The inside diameter of the ferrule is generally slightly larger than the outer diameter of the pipe. The ferrule may be disposed on the pipe adjacent the end where the valve is to be attached.
An internally threaded nut may be placed on the pipe along with the ferrule. After the nut and ferrule have been placed on the pipe, a valve fitting having an externally threaded receptacle is placed in fluid connection to the pipe. The connection between the valve fitting and the pipe is generally achieved by screwing the nut onto the externally threaded receptacle, with the ferrule disposed between the nut and the receptacle. The nut is tightened onto the receptical to create a tight press fit between the receptacle, ferrule and the nut. The tight fit creates a substantially fluid-tight connection. A general description of the use and structure of compression fittings in metal tubing is disclosed in U.S. Pat. No. 4,260,182, the substance of which is incorporated herein by reference.
Over time, the valve may break down and require replacement with a new valve. If the new valve is connected to the existing nut and ferrule, a fluid-tight seal may not be achieved. In addition, the new valve may have a receptical that is a different size from the previous receptical, thereby requiring a different sized nut. Therefore, the original nut and ferrule are generally replaced with a new nut and ferrule. However, before the new nut and ferrule can be disposed on the pipe, the old nut and ferrule are typically removed.
Removing the ferrule from the pipe to allow a replacement valve or fitting to be connected can prove to be difficult. As such, cutting the pipe or metal tubing upstream from the ferrule is one way of allowing the placement of a new valve. However, after cutting the pipe, the remaining portion of pipe may be too short to connect with a replacement valve or fitting. In other words, the pipe may not extend out far enough from the wall or other surface to allow connection of a new valve. Furthermore, cutting the pipe may make re-connecting the other end of the valve to the adjacent pipe very difficult. For instance, the valve may no longer be aligned with the adjacent pipe. As such, cutting of the pipe may require a new section of pipe to be welded to replace the removed pipe. The welding of the new pipe is expensive and time consuming.
Therefore, prior art techniques are used to pull the ferrule off of the pipe in an attempt to avoid the cutting of the pipe, however, such tools may damage the pipe. For example, prior art ferule pulling tools may use a vice and pulling mechanism that could flare or “mushroom” the end of the pipe, or otherwise deform a portion of the pipe. As such, even after using the tool it may be necessary to cut the pipe to remove the deformed portion. In addition, such ferule pulling tools are bulky and it may be difficult to operate such tools in small confines, where plumbing valves are typically hidden from view. An example of one type of ferule pulling type of device may be found at U.S. Pat. No. 4,672,731, the substance of which is incorporated herein by reference.
As is apparent from the foregoing, there exists a need in the art for an improved tool for removing a ferrule from a pipe. The present invention addresses this particular need, as will be discussed in more detail below.